Optical rib waveguides based on sol-gel derived silica–titania films

Rib channel waveguides were produced with the application of chemical wet etching of the sol-gel derived silica–titania (SiO2–TiO2) waveguide films. The silica–titania films were etched in water solutions of ammonia fluoride. In the etching process, the waveguide films were selectively masked with a photoresist. This paper presents the theoretical analysis of rib channel waveguides as well as the results of experimental research on slab and rib channel waveguides. For slab waveguides the attenuation of 0.15 dB/cm was obtained, and for the produced single mode rib channel waveguides, the attenuation of 1.7 dB/cm was obtained.